* use gofmput to format code
* use gci to format imports
* reconfigure gci
* linter autofixes
* rearrange imports a little
* export GOOS=windows golangci-lint run ./... --fix
* fileserver: Support virtual file systems (close#3720)
This change replaces the hard-coded use of os.Open() and os.Stat() with
the use of the new (Go 1.16) io/fs APIs, enabling virtual file systems.
It introduces a new module namespace, caddy.fs, for such file systems.
Also improve documentation for the file server. I realized it was one of
the first modules written for Caddy 2, and the docs hadn't really been
updated since!
* Virtualize FS for file matcher; minor tweaks
* Fix tests and rename dirFS -> osFS
(Since we do not use a root directory, it is dynamic.)
This commit fixes the `sortByNameDirFirst` variable inside fileserver to
match what browse's default template has.
Co-authored-by: Francis Lavoie <lavofr@gmail.com>
